It is easy to miss the spirit gate that guards the entrance to Phiyer, a remote village in northern Laos. Half submerged in weeds beside a field of towering sugarcane, the simple wooden structure resembles a set of miniature rustic goalposts. Look closely, however, and you will notice it is strung with roughly carved swords and assault rifles made of bamboo. The villagers believe the gate wards off disease and evil spirits.

A modern epidemic now threatens Phiyer and no amount of ancient voodoo will protect it. The village lies in the mountainous Sing district, which shares its northern border  and the mighty Mekong River  with Burma. There, in semiautonomous fiefdoms ruled by heavily armed militias, secret factories spew out hundreds of millions of tablets of methamphetamine, a highly addictive drug better known there by its Thai name yaba (crazy medicine). From Burma, the drug is spirited across the ill-policed Mekong into Laos and its four other neighbors  China, Thailand, Vietnam and Cambodia  and onward to other parts of Asia and as far afield as New Zealand. Sleepy Phiyer sits on one of Asia's  and the world's  busiest drug-trafficking routes.
(Read about an herbal remedy for drug users in Cambodia.)

Northern Laos was once notorious for opium, and its derivative, heroin. Together with Thailand and Burma, this mountainous region makes up the Golden Triangle, which once provided at least half of the world's opium supply. Burma alone produced nearly 1,800 metric tons in 1993, estimates the U.N. Office on Drugs and Crime (UNODC). A decade later, after eradication programs in all three countries, opium production in Southeast Asia fell to about 350 metric tons. Factor in global trends  soaring opium production in Afghanistan, or Colombia's once growing share of the U.S. heroin market  and the Golden Triangle's days as the world's biggest opiate factory seemed numbered.

But the Golden Triangle  probably named after the gold once traded for opium  didn't die. It did what any good business does in our globalized age: expand its markets and diversify its product range. First, new customers were found for an old product: heroin that once moved south into Thailand, and then on to international markets, now primarily moves north into China, where 2.2 million users consumed 45 metric tons of mostly Burmese heroin in 2008, says the UNODC. Second, the Golden Triangle was by the late 1990s manufacturing the product that symbolizes its renaissance. Methamphetamine is Asia's favorite high. Its popularity is a symptom of the region's astonishing economic growth. This new prosperity has liberalized trade, reduced transportation costs, accelerated the movement of people and products, and created a vast middle class with cash to burn. All this has helped traffickers shift their product to millions of fresh consumers.

Methamphetamine can be eaten, smoked, snorted or injected. It boosts energy, self-esteem and sexual pleasure, but can also cause paranoia and aggression. It is highly addictive: withdrawal symptoms include fatigue, anxiety and long-term depression. That addiction is difficult to treat, partly because the drug's popularity straddles social and economic divides, town and country, work and leisure. The same drug that helps laborers endure backbreaking work in the fields allows affluent urbanites to party till dawn.
(Read more about Burma's opium production.)

Compare this with the Golden Triangle's traditional crop. The second half of the opium poppy's botanical name (Papaver somniferum) means "to cause sleep"  hardly the drug for countries aspiring to double-digit growth. Opium, the thinking goes, is for old people and "backward" hill tribes, while heroin is for losers; but methamphetamine has a social acceptance, particularly among young Asians, that rightly terrifies governments.

It gets worse: the Golden Triangle is also producing more opium. In 2007, after six years of decline, poppy cultivation in Burma began increasing again. The country produced an estimated 580 metric tons of opium last year, a whopping 76% increase over 2009. Cultivation is also creeping up again in Laos and Thailand. "We are worried about the prospects of a further expansion in 2011," says Gary Lewis, UNODC representative for East Asia and the Pacific. "The international community has taken its eye off the ball on drug production and trafficking in Southeast Asia."

A New HubGolden Triangle traffickers began favoring Laos after the Thai government's brutal "war on drugs" in 2003 killed thousands of people and disrupted smuggling routes between Burma and Thailand. An alternative route lay through northern Laos, where a network of roads was being constructed to link the booming economies of Thailand and China. Roads once impassable in the rainy season are now plied year-round by hundreds of vehicles carrying untold millions of pills. In February 2010, police there arrested four men with 21 million yaba tablets  the largest-ever seizure of the drug in Laos.

Wherever you go  Laotian villages, Thai construction sites, nightclubs in Shanghai, Tokyo or Dhaka  methamphetamine is as easy to buy as a bowl of noodles. Amphetamine-type stimulants, which include yaba and Ecstasy-group substances such as MDMA and ketamine, are becoming first-choice drugs in mainland China, Taiwan, Japan and Southeast Asia, reported the UNODC in December 2010. In Thailand, 4 out of 5 drug users who received treatment in 2009 were treated for yaba. Asia's appetite for narcotics is now so prodigious that it attracts criminal organizations from across the planet. Iranian and West African drug mules are now routinely arrested at Asian airports.
(See pictures of cocaine country: Guinea-Bissau and Liberia.)

Methamphetamine is cheap and easy to make. Unlike opium fields in highland Southeast Asia, meth labs can't be detected by satellite. "You can target something that grows out of the ground much more easily than a laboratory that can be dismantled and moved within a couple of hours," says Thomas Pasquarello, who until December was regional director for the U.S. Drug Enforcement Administration (DEA). "And these laboratories are capable of producing huge amounts of methamphetamine."